Fuel gauge stopped working on 318iS

[DORIFT]

Hi today the fuel level gauge on my car suddenly stopped working while i was driving... It now sits on EMPTY with the lights glowing... There is almost a full tank in there...

The needle went straight from Full to EMPTY... any possible causes? I don't think its a fuse... or is it??

Any help would be greatly appreciated!

Cheers!

[Stephen 325TDS]

Dorift,
under the rear seat on RHS, there's a fuel pump/sender unit. This registers the quantrity of fuel left in the car. It may well be this that is causing the problem. I would think that it isn't a fuse - the light probably wouldn't be on.

Stephen

[DORIFT]

Thanks for the reply!

So do i have to buy a new unit and replace it?
is it easy to do DIY?
how much approximately the new unit will be??

sorry for the questions as i dont know much about BMWs....

[Stephen 325TDS]

I've heard that the contacts can be cleaned, and that it is sometimes cured by doing this, but I didn't do this myself as the pump had also failed on mine.
A new pump cost me £115 a couple of years' ago from an independent supplier - I'd imagine that the cost from BMW would be greater.
The transplant will take you less than half an hour, and that's leaving a big margin for someone who's not too sure what needs to be done.
First thing ... get yourself a manual.
Second thing ... I neglected to tell you that there's a second, separate, sender unit in the LHS of the tank (it isn't part of a pump).
I would remove both, and check the contacts, before I spent any money. Also remember, disconnect the battery and run the tank low on fuel before you examine these units. You don't want any sparks!

Stephen

[DORIFT]

Thanks again for the reply

I managed to open up the fuel celler under the back seat today and found out that one wire that connects the fuel sender was completely disconnected from its terminal, therefore i took out the whole assembly and weld the wire back onto its terminal... thought i fix the problem but then i started up the car, the needle still sits on EMPTY position....

What could be wrong... but in saying that i haven't got a chance to go have a look at the second fuel tank on the left hand side...

any suggestions??

[Stephen 325TDS]

I'd try the LHS.

Stephen

[EdgePerformance]

Originally Posted by DORIFT

Thanks again for the reply

I managed to open up the fuel celler under the back seat today and found out that one wire that connects the fuel sender was completely disconnected from its terminal, therefore i took out the whole assembly and weld the wire back onto its terminal... thought i fix the problem but then i started up the car, the needle still sits on EMPTY position....

What could be wrong... but in saying that i haven't got a chance to go have a look at the second fuel tank on the left hand side...

any suggestions??

It is either the actual gauge in the gauge cluster, or the sensor that is inside the gas tank that is part of the Fuel Pump and Sender. You can get part for inexpensive if you don't mind used parts that are guaranteed to work or do your homework on new prices.

Jared

[jeffreyb4me]

this "fuel gauge to empty" and warning lamp on is a common complaint after fill-ups is a common and new problem on later BMW's.....the claim is that sulfurs in the fuel causes a build-up on the sensor contacts and is agrevated during the filling process. having been a BMW tech. for so long though, I 'know' it's a design/material/vender problem and BMW's fix is sensor replacement but as with the early M-60 engine failures, we were replace the culpret with the identical component [short block] until an engineering solution had time to reach us.